As science and technology develop and various audio and video playing products prevail, people have higher and higher requirements on sound quality, and correspondingly have higher and higher requirements on headphone quality. Specifically, in addition to requiring that headphones have high, medium and low clearly-layered and opera-like surrounding sound quality performance, people further hope that headphones do not cause fatigue and will not cause damage to people's hearing even though people use headphones for a long time period.
Currently, headphones are structurally classified roughly into two types: closed type and open type. The closed type headphone means employing a closed type sound chamber structural design, enclosing the sound emitted by a headphone loudspeaker unit in the space between the interior of the headphone housing and the wear's ears so that a person nearby cannot easily hear the sound produced by the headphone. The closed type headphone is advantageous in concentrating the sound produced by the headphone loudspeaker unit at the entrance of the ear canal and strengthening the bass effect, but disadvantageous in that the headphone sound is excessively concentrated at the center of the head and is not apt to create a feeling with surrounding sound, and meanwhile use for a long time period is likely to cause fatigue to the wearer and damage to the wearer's hearing. On the contrary, the open headphone causes the sound produced by the headphone loudspeaker unit to be locally heard by a nearby person, the sound is not concentrated at the center of the head, the sound field is open and natural, and use for a long time period is not apt to cause fatigue. However, the open type headphone cannot exhibit high-quality bass performance.
In the prior art, to make the open type headphones have high-quality bass performance, generally the space of a rear headphone chamber is enlarged or a loudspeaker unit with a large diameter is employed. That makes the overall size of the headphones larger and does not facilitate light-weighted and miniaturized design of headphones.
Therefore, it is desirable to design an open headphone integrating advantages of the closed type and open type headphones. The open headphone has high-quality bass performance, and other advantages, such as that the sound field is open and natural, that the user is not easy to become fatigue after long-term use, and that it will not cause damage to people's hearing. Furthermore, the whole headphone structure is light and small and easy to carry and use.